Performing global management operations on the Internet in an efficient way is difficult, because of the continuous changes to the Internet topology, its large number of nodes and the lack of an up-to-date global data...
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ISBN:
(纸本)0780367197
Performing global management operations on the Internet in an efficient way is difficult, because of the continuous changes to the Internet topology, its large number of nodes and the lack of an up-to-date global database. In practice, these difficulties appear in the management of large private IP networks and large autonomous systems, which form the sub-topologies of the Internet and are under independent administration. This paper introduces the echo pattern, a scheme for distributing management operations, which addresses these difficulties. Management operations based on this pattern do not need knowledge of the network topology, they can dynamically adapt to changes in the topology, and they scale well in very large networks. A management operation based on the echo pattern has two phases. In a first phase, the network is being flooded with management commands to be run on the network elements. In the second phase, the results of the local management operations are aggregated inside the network. We analyze the echo pattern with respect to time and traffic complexity and compare its performance to that of a centralized management scheme. Our results show that "typical" echo-based management operations could be executed within some 18 seconds on the entire Internet. This short time is due to (1) the high degree of parallelism and distributed control in this pattern and (2) some specific properties of the Internet topology.
Efficient execution of applications requires insight into how the system features impact the performance of the application. For distributedsystems, the task of gaining this insight is complicated by the complexity o...
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ISBN:
(纸本)0769507840
Efficient execution of applications requires insight into how the system features impact the performance of the application. For distributedsystems, the task of gaining this insight is complicated by the complexity of the system features. This insight generally results from significant experimental analysis and possibly the development of performance models. This paper presents the Prophesy project, an infrastructure that aids in gaining this needed insight based upon one's experience and that of others. The core component of Prophesy is a relational database that allows for the recording of performance data, system features and application details.
In some scenarios involving on-line transaction processing within a distributed database, it is desirable to synchronize transactions in a manner that guarantees conflict equivalence with a serial schedule ordered by ...
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ISBN:
(纸本)076950728X
In some scenarios involving on-line transaction processing within a distributed database, it is desirable to synchronize transactions in a manner that guarantees conflict equivalence with a serial schedule ordered by original transaction start times while providing each transaction with an anomaly serializable isolation. Few theoretical concurrency control algorithms guarantee such a conflict equivalence, and we are unaware of any protocol that accomplishes this while supporting real-world issues such as out-of-order transaction messages, out-of-order operation executions, and out-of-order transaction committals without the burden of explicit readset and writeset declarations We describe an algorithm that provides this guarantee mid supports these issues while requiring only table-level writeset declarations.
parallel programming with distributed object technology becomes increasingly popular but shared-memory programming is still a common way of utilizing parallel machines. In fact, both models can coexist fairly well and...
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ISBN:
(纸本)354067442X
parallel programming with distributed object technology becomes increasingly popular but shared-memory programming is still a common way of utilizing parallel machines. In fact, both models can coexist fairly well and software DSM systems can be constructed easily using distributed object systems. In this paper, we describe the construction of a hybrid programming platform based on the ARTS distributed object system. We describe how an object-oriented design approach provides a compact and flexible description of the system components. A sample implementation demonstrates that three classes of less than 100 lines of code each suffice to implement sequential consistency.
In the world of pervasive computing where large management systems, as well as small devices, all become interconnected, the problem of the configuration and management of networks is becoming increasingly complex. Sy...
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ISBN:
(纸本)0769508197
In the world of pervasive computing where large management systems, as well as small devices, all become interconnected, the problem of the configuration and management of networks is becoming increasingly complex. System administrators have to deal with many problems due to the increasingly, distributed architecture of systems. Jini, a new paradigm for the development and management of distributedsystems, provides mechanisms that enable systems to plug together to form an impromptu community. This practice report demonstrates how Jini can be applied in an industrial environment. or more exactly how it can be used in the integration of embedded devices on-board trains in the back-office IT infrastructure of railway operators. We present two use cases: the first is about an on-board service that allows for remote access to an onboard diagnosis database;the second is about automatically installing new services on-board trains. The results are encouraging and prove that Jini is the appropriate technology to link application servers and service gateways in embedded servers.
Design on the Web raises challenging questions concerning how users interact with objects, applications, and other users. In this work, we propose a collaborative and interactive client-server design framework and imp...
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ISBN:
(纸本)0769509363
Design on the Web raises challenging questions concerning how users interact with objects, applications, and other users. In this work, we propose a collaborative and interactive client-server design framework and implement a room design system for our study. We hare integrated technologies used in distributed computation (Java and CORBA) and computer graphics (VRML). It divides the design process into three tiers. first, collaborative and interactive design, viewing, and publishing. Second, scene generation. Third, scene database management. Our system can be applied in Electronic Commerce to improve the existing systems by allowing customers to select furniture and to visualize the whole furnished room in 3-D.
The most costly spatial operation in spatial databases is a spatial join with combines objects from two data sets based on spatial predicates. Even if the execution time of sequential processing of a spatial join has ...
The development of control systems often implies necessity of the organization of parallel computing processes or the implementation of software of distributed data processing. Solving this problems we should carry ou...
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ISBN:
(纸本)0780364864
The development of control systems often implies necessity of the organization of parallel computing processes or the implementation of software of distributed data processing. Solving this problems we should carry out such stages as constructing system structure, developing scheme of processes communication, choosing special language tools of the parallel programming. Such formal tools of simulation as Petri nets and its extensions can lighten the resolving of this problems. The communication of parallel processes is described by the net structure, which can be easily obtained from the process state graph and the. algorithm implemented by this process. It is important to note that Petri nets allow to describe asynchronous and parallel independent events. Occurrences of transitions act as events and result in creating, moving and deleting tokens. In this case the processes are represented by tokens, and the cortege of token attributes acts as a data segment of the process. To this effect the object-oriented modification of the hierarchical E-nets is developed. At the developing of the given E-nets modification we have been concentrated on the creating of the open program interface. By this we have achieved two important factors. first, ne can bind the net events and any calculations or input/output operations by any available code library. Second, constructed in that way the kernel of a distributed system is independent and can be used in a resulted software product. Though the development of the corresponding design tools are not finished, the effectiveness of the given approach is confirmed by the results of scientific work of authors.
The paper presents PowerMANNA - a distributed-memory parallel computer system based on the 64-Bit PowerPC processor MPC620. The PowerMANNA node architecture supports all the sophisticated features of the MPC620 and in...
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The paper presents PowerMANNA - a distributed-memory parallel computer system based on the 64-Bit PowerPC processor MPC620. The PowerMANNA node architecture supports all the sophisticated features of the MPC620 and incorporates important architectural concepts that allow us to exploit the performance of modern superscalar microprocessors in the context of massively parallel supercomputing. The two-way processor nodes of PowerMANNA are embedded in a powerful communication system supporting low-latency communication and maximum connectivity. Processing and communication performance of an eight-node prototype are shown and compared with shared-memory machines and clusters. In the course of the presentation, experience gained with the PowerPC MPC620 processor is discussed.
We first describes the state of the art in models of concurrency. The models are analyzed along two dimensions: communication and computation. The paper then discusses some problems which make it difficult to realize ...
ISBN:
(纸本)9780818608933
We first describes the state of the art in models of concurrency. The models are analyzed along two dimensions: communication and computation. The paper then discusses some problems which make it difficult to realize large-scale concurrent systems. Such problems include compositionality, heterogeneity, debugging, resource management, and concurrency control. Some useful comparisons are drawn to problems in distributeddatabases and it is argued that solutions to these problems cross disciplinary boundaries. Finally, the paper discusses trends in building concurrent computers and provides some expectations for the future.
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